FOXO1 and premature menopause: Other follicular development-related genes include Foxo3a and Foxo1. Ding et al. found that UCMSCs on a collagen scaffold can activate primordial follicles in vitro via phosphorylation of FOXO3a and FOXO1, and transplantation of collagen/UCMSCs to the ovaries of POF patients can elevate estradiol concentrations, improve follicular development and increase the number of antral follicles (Ding et al., 2018).